System monitor says Cinnamon is ~95% busy most of the time, Web content goes up to 40%
This lap has single core 32-bit 1.7GHz processor, 2GB so not much these days, but still should be OK since I tried w'7 (from distribution disk, but decided not to register because w'7 did not support built-in sound and WiFi adapter) and the browsing and general responsiveness to mouse was adequate. So it was when Cinnamon was booted from stick.
BTW, I found relevant
discussion on Linux forum, will try that